1. Field of the Invention
The present invention is directed to an LED (light emitting diode) lamp which finds particular use as a wayside signal for a railway.
2. Discussion of the Background
The railroad industry utilizes wayside signals to indicate authorization for trains to proceed or to stop at certain positions on railroad tracks. Currently, such wayside signals utilize incandescent lamps to provide the indication for the train to proceed or not.
However, the use of incandescent lamps in the wayside signals results in certain drawbacks. First, the life of incandescent lamps is relatively short, i.e., an incandescent lamp typically burns out in a relatively short period of time of approximately 6 to 12 months. This may be particularly problematic in wayside signals for railways as such wayside signals may often be placed at remote locations along railroad tracks. As a result, it is often inconvenient and time consuming for maintenance personnel to replace a burned out wayside signal. Also, any time a wayside signal burns out safety concerns are raised and the use of certain railroad track sections may be prohibited, resulting in a loss of operating efficiency, requiring track reroutings, etc. A further drawback with wayside signals utilizing incandescent lamps is that they are relatively energy inefficient.
Accordingly, one object of the present invention is to provide a novel wayside signal for a railway which can overcome the drawbacks in conventional wayside signals.
A further object of the present invention is to provide a novel wayside signal for a railway which results in reduced maintenance costs and increases energy efficiency in comparison with conventional wayside signals utilizing incandescent light bulbs.
A further object of the present invention is to provide a novel wayside signal for a railway which provides the above-noted benefits without sacrificing operating performance and reliability.
To achieve the above-noted and other objects, the present invention is directed to a novel wayside signal for a railway which includes a plurality of light emitting diodes housed in a housing. The light emitting diodes output the indication signals. Further, the light emitting diodes are configured on a first circuit board which is thermally coupled to the housing. The housing may also include heat sink fins to dissipate heat generated by the light emitting diodes and associated driving circuitry for driving the light emitting diodes also contained within the housing. An additional light emitting diode may also be contained within the housing to point in an opposite direction than the indication signal light emitting diodes, which additional light emitting diode may be formed on a second circuit board with the driving circuitry. The additional light emitting diode provides an indication to anyone behind the wayside signal as to the indication of the wayside signal.
As a further feature in the present invention, the wayside signal is optimized for thermal efficiency and to be sealed against the elements. In regard to thermal efficiency, the first circuit board may be metal clad and the housing may be made of die cast aluminum and black anodized.
As a further feature in the present invention, a plastic insulator may be attached to the housing onto which a lamp base may be swaged. Further, the wayside signal of the present invention can be utilized with existing wayside signal sockets and circuitry.